Broadcasting information to more than one user in a wireless system can reduce the demands on the communication capacity of a wireless network by allowing more than one user to receive the information without requiring more than one point-to-point transmission. The benefits of broadcasting information are especially important for multimedia content, such as financial news-clips or graphics needed by business users, or sports-clips, weather forecasts, music, videos, and movies that are targeted to consumers.
Wireless access technologies such as High Data Rate (HDR) enable high-speed wireless data services (see P. Bender, et al., “CDMA/HDR: A Bandwidth-Efficient High-Speed Wireless Data Service for Nomadic Users”, IEEE Communications Magazine, July 2000, and 3GPP2, “Draft Baseline Text for 1×EV-DO,” Aug. 21, 2000). The Telecommunications Industry Association (TIA) has adopted HDR as a standard in the CDMA2000 family of wireless technology standards. The service is formally referred to as HRPD (High Rate Packet Data) and is also known as IS-856. Because TIA adopted HRPD as an EVolution of the current 1×RTT standard for high-speed data-only (DO) communication, the standard is also known as 1×EV-DO. An example of a 1×EV-DO network is Airvana's All-IP 1×EV-DO Wireless Data Network.
1×EV-DO systems are typically implemented using a radio access network (RAN) 20 as shown in FIG. 1. The RAN 20 converts content to a format that is amenable to transmission over an airlink 12 to access terminals 10. The access terminals 10 may be laptop computers, personal digital assistants (PDAs), dual-mode voice/data handsets, or other devices with built-in 1×EV-DO support.
The 3rd Generation Partnership Project 2 (3GPP2) is developing a standards family describing a broadcast service called Broadcast and Multicast Service (BCMCS) in cdma2000 Wireless IP networks (see 3GPP2, “CDMA2000 High Rate Broadcast-Multicast Packet Data Air Interface Specification”, C.S0054 (February 2004) and 3GPP2, “BCMCS in cdma2000 Wireless IP Network”, X.S0022 (December 2004)), both incorporated here by reference (collectively “the Standard”). BCMCS enables operators to deliver broadcast media (including multimedia applications) less expensively than having individual users obtain the same streams through point-to-point connections.
Referring to FIG. 1, the Standard describes the airlink interface as well as higher-layer protocols between an access terminal (AT) 10 and the radio access network (RAN) 20. The Standard defines a network reference model describing the logical elements that make up BCMCS. FIG. 2 shows a simplified version of this reference model.